Next, add some buttons

Then give the buttons a function to call

# function to print out the name of the button pressed
# followed by the contents of the two entry boxes
def press(btnName):
print(btnName)
print app.getEntry("userEnt")
print app.getEntry("passEnt")
# changed this line to call a function
app.addButtons( ["Submit", "Cancel"], press, colspan=2)